Hey.
There is no documentation on how to make change for the condenser as far as I know. The repo is on:
https://gitlab.syncad.com/hive/condenser

You don't need to fork, just clone the repo, create a feature branch, commit and push your changes and create a merge request to the develop branch. For running the condenser locally, just run yarn to install all the NPM packages and then run yarn start. Once the merge request to develop has been approved, your changes will be deployed to https://staging-blog.hive.io where you can get others to test them.

The Condenser is based on an old version of React / Typescript.